Pneumatic-dispatch-tube system



March 18, 1930. E, wElGELE m 1,751,115

PNEUMATIC DISPATCH TUBE SYSTEM Filed Dec. 9, 1924 2 Sheets-Sheet 1 vweutoz 33x a t/12mm d March 18, 1930. E. WEIGELE PNEUMATIC DISPATCH TUBE SYS TEM Filed Dec. 9, 1924 2 Sheets-Sheet 2 VIIIIIII A Patented Mar. 18, 1930 UNITED STATES PATE FIE EDMUND WEIGELE, OF BE GENEIELD, NEW JERSEY, AssIGNoE T G. a G. ATLAS sYs- TEMs, 1110., OF NEW YORK, n. Y., .A. coEPoEA'rIon on NEW YORK PNEUMATIC-DISPATCH-TUBE SYSTEM Application filed December 9, 1924. Serial No. 754,698.

This invention relates to pneumatic dispatch tube systems, and particularly to such systems of the type known as open systems. 1

By the term open systems I mean systems in which each line is provided with an open end or bell mouth, into which carriers may be inserted directly and without the preliminary opening 01": a gate or Valve, or, in other words, systems in which each line is normally open to the atmosphere at one end.

In'these systems each line generally communicates at the delivery end with an exhauster of some suitable type so that when a carrier is inserted in the line it will be drawn through it by suction. Of course, it the tullsuction is maintained on the system at all times, whether there is any carrier to be transmitted or not, there will result a great waste of power.

The general object of the present invention is to provide a simple and etficient controlling device for such systems, which will reduce this waste of power to a minimum. 3

The more specific objects of my invention will appear more fully hereinafter.

In the accompanying drawings Fig. 1 illus trates a typical open; tube system to which my invention is applied. Fig. 2 is a sectional view of the preferred form of my controlling device, with the valve in its normal cracked position. Fig. 3 is a fragmentary view of the valve of Fig. 2 showing the valve in its open or transit position.

Referring first to Fig. 1, 10, 11 represent the transit tube. 'In department stores and similar places where these systems are used extensively, the open end or bell mouth 12 is usually situated at the central cashiers station A, as is the delivery end 13 which is provided with a door 14:, normally held closed as shown, by spring means. Intermediate the two ends 12 and 13 is located the salesmans station B where the line is provided with a carrier exit 15, normally closed by the spring pressed door 16, and with a carrier entrance 17, normally closed by a spring pressed door 18. Suction for conveying carriers through the transit tube 10, llis provided by an exhaust drum 19, or equivalent device, through the exhaust tube 20 which commuthe money and the sales slip in the usual cylindrical carrier and, opening the door 18, inserts the carrier into the tube 11. The suction applied adjacent the delivery end draws the carrier to that end of the system, where it pushes open the-door 1 1, and drops out of the tube. The cashier then makes the necessary change in the contents of the carrier and places it into the tube 10 through the open end, or bell mouth 12. The doors 14, 16 and 18, being closed, the suction applied at the delivery end 13 is effective to draw the carrier through the tube 10, from which it emerges at the salesmans station 13 through the'exit 15, pushing open the door 16 in a manner well understood.

acter, unless some means are provided for preventing it, a large volume of air will constantly be sucked through the transit tubes,

It is evident that in a system of this charwhether any carriers are being transmitted or Y r not. This, of course, is very wasteful of power. Accordingly I have provided,betw.een the exhauster 19 and the exhaust tube 20, a controlling device 21, which normally reduces the flow of air through the transit tubes to almost nothing, but which automatically applies full suction the moment a carrier is inserted into the transit tube. As soon as the carrier leaves the tube the suction is again cut down.

The'construction and operation of this controlling device can best be understood from Figs. 2 and 3. This device includes a port 22 and a valve 23 for controlling that port. This-valve, which may be of any suitable construction, such as those here shown, is connected by means of a valve stem 24 with a diaphragm 25. This diaphragm divides the casing in which it is mounted into two chambers, 26 at the left (as viewed in Fig. 2) and 27 at the right. Thechamber 26' is maintained at atmospheric pressure 7 through the opening 28, and the chamber 27 is'normally maintained at the same pressure 1 as the exhaust tube by the communicating passage 29. The normally closed valve when opened admits the atmosphere .to. the chamber 27.

I shall now describe the way in which the valve -23.is opened automatically upon the insertion of a carrier into the tube.

' WVith the valve in the almost-closedbr cracked position. illustrated in Fig. 2, but a slight amount of. air is drawntlirough the exhaust tube20 and transit tubes 10, ll'by the exhaust er. Since the transit tubes are normally open to the atmosphere at the end 12 the pressure within those tubes and within the exhaust tube 20 is normally at substantially atmospheric pressure, the flow of air through the valved port 22 being insuf- "ficient' to reduce the pressure materially.

Thegspring' 31 is ofsufiicient force to hold the valve 23. in the position shown in Fig. so long as the conditions just described exist inthe tube system. However, as'soon as a carrier is inserted either into'the open bell mouth 12 or into the entrance 17 of the transit tubes, the portions of the tubes in advance of the carrier are cut oil from communication with the atmosphere, as, of course, is the exhaust tube 20. Immediately the small flow of air through the cracked valve 23 estabof air through the system and transmits'the carrlerthrough the tube, from'w-hich it is delivered through the door 14 or the door 16,

as the case may be.

Uponthe delivery; of the carrier there is, of course, a rush ofair through the port 22. This rush of air operates by its kinetic energy upon thevane 32 to which the valve 30 is connected and thus opens the valve'30-and admits the. atmosphere to the chamber 27.

r The pressure in the chamber 27 isthus increased sufiiciently so that the spring 31 is able to restore ,the va1ve23 and the diaphragm 25 to their normal positions of Fig. 2. I have foundthat with a device of the character just described it is desirable to construct the valve23'in such away that-thediaphragm' 25 will not have to push the entire valveopen against the current of air flow. In the drawings I have shown three'forms of valve designed with this purpose in mind.

Thefirst form is illustrated in Figs. 2 and ,3, to which I have already referred generally. "I shall now describe this valve in detail.

'This valve-of Figs. 2and 3 includes a plulo'ck nut 41.

rali'ty of separate disks or valve members, as,

for example, the three which are marked 23, 23 and 23. The largest disk 23 is carried by a sleeve 33. Within this sleeve 33 is mounted the valve stem 24 which, at its inner end,is tubular and near its outer end is provided with a shoul-der35 With-whichthe in-' .termediate disk 23 is shown in contact in Fig. 3. The outer ,or smallest ,disk,.23, is

.adjustably securedflto a, reduced portion of this valve stem, as indicatedin'Figs. 2 and. 3. The inner tubular end. of the valve stem 24 is secured to the center of the diaphragm 25 by; means of bushings 36, or in any other suitable manner. Within this tubular portion of the valve stem-24 is located the slidable rodi37 provided with ears- 38 which pass through slots 39-in-the tubular portion of the valve stem 24and'are adaptedto contact with the sleeve 83, as indicated-in Figsx2 and 3. r

The distance which the disk 23 is to be spaced from thevalve seat when-no tube is v intransitis determined by the adjusting screw to, which is provided with asuitable This screw contacts with the tiQQ end of the rod 87 and-thus: limits thee-movement ofthat rod and of the-sleeve and the disk 23 to the" left. 7 I

Whenthediaphragm 25- is. -moved- ,.to the right in the manner-above described-upon the insertion of aearrierin-to the line, it"does not move theentire valve' 23 simultaneously,but

first moves the valve stem 24 and the smallest disk 23= which is secured to thatstem. "Thisp :lOO

off-course, resu'lts in the uncovering of the auxiliary port'42 in" the intermediate disk 23 and increases the flow o'rlair through the port 22. Asthe movement of the diaphragm V .25 and the stem24; continues -to the right,

the shoulder'85 of thastem-Ql littsthe inter- I mediate disk T23 from-its seat against the;

largest disk 23 -and thusaincovers the auxiliary port i3. in the largest disk and further increases the flow through the port 22. Fina-lly, upon the continuedmovemcnt to the right or" thediaphragman'd the valve stem '24:, the left hand margin of the slotsk39 inthat stem contact with the ears'SS of the rod 37,-.and in their further movement the diaphragm and stem therefor carry with them the :sleeve 38and disk 28 The result of this finalmovement is to open the port 22' comipletelyrand thereby establish a iullflowof air-throughit; The extent towvhich the valve: stem 24::may travel in opening the. valve is determined by the adjusting screw 44, which-has a; lock nut45. I 7

From this description of the progressive opening of the several .valve disks. itv isievident that the amount of force-whiehwould be required to open the entire valve 23 atone time against the. air currentis very materially reduced. Thus the ClQVlCGi;lS I8Ildere,d Iml1Ch more sensitive, and itIoperatesmore rapidly.

The closing of the three-part valve 23 upon the return of the diaphragm 25 involves merely a reversal of the operation above described. That is, the valve stem 24, which is drawn back by the diaphragm, first seats the smallest disk against the intermediate disk, then seats the intermediate disk against the largest disk, and finally brings the three disks together, back into the position of Fig. 2. Of course, it is not essential that the number of disks or valve members be three. There may be only two, or there may be more than three, depending upon the particular conditions encountered. Also, the normal leakage need not be between the first disk and the main port, but may be between another of the disks and the auxiliary port which it overlies.

Of course, many other types of valves may be used in place of that here shown, it being essential merely that the valve shall be so constructed that it may be opened quickly by the application of a comparatively slight force.

I am aware that it has heretofore been proposed to insert in the exhaust tube of a pneumatic dispatch system, or between the exhaust tube and exhauster, a controlling device adapted to operate automatically upon the insertion of a carrier into the tube for establishing the full flow of air through the tubes and to reduce the flow at times when no carrier is in transit. The Libby Patent No. 968,576, for example, suggests such a device, but the device shown in that patent is vided an extremely simple and efiicient control device for open vacuum systems by means of which the. amount of power employed when no carrier is in transit is reduced to a negligible quantity and a great saving is thus effected. Also, by reason. of-the simple and direct controlling action, this device operates with great rapidity and thus makes possible the most eflicient operation of the tube system as a whole.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any mechanical equivalents of the features shown and described, or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

What I claim is: v

1. Power control apparatus for a pneumatic dispatch system of the vacuum miniwith a projection extending through a slot in said stem, and a valve for controlling carrier impelling air flow through the tube, said valve comprising an element operated directly by said stem, and an element operated by said stem through the medium of said rod.

2. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type comprising a transmission tube, a pneumatic exposed on one side to the air pressure in said tube, a stem connected to said pneumatic for movement thereby and having a shouldered portion, a rod slidably mounted in said stem and provided with a projection extending through a slot in said stem, and a valve for controlling carrier im- .pelling air flow through the tube, said valve said pneumatic for movement thereby and having a shouldered portion, a rod slidably mounted in said stem and provided with a projection extending through a slot'in said stem, and a valve for controlling carrier impelling air flow through the tube, said valve comprising an element secured to said stem,

an element operated by the shouldered portion of said stem, and an element having a sleeve connected thereto for operation by said stem through the projection on said rod.

EDMUND WEIGELE. 

